...take charge or do it yourself (soloing).
Although even when leading, a lower level of skill/knowledge of the game/quest is usually not the problem. The real issue is people's incapability to listen and not being open to learn - and/or admit they dont know a quest, and that they messed up. There is a lot of assumption going on and when things go hairy its actually the party leaders fault for not instructing people - even though the LFG said "TR zerg for xp, know the quest". You cant zerg a quest for XP if you dont know it, and if you dont, you either dont join, or you join and ask for info. And of course, you bring pots and proper gear and, last case scenario, if you cant help at all, at least keep yourself alive and enjoy free XP. Which doesnt happen often.
Its understandable that conflicts can arise when people are at very different levels of experience with the game - a completionist teaming with a total new player. Communication and being pro-active goes a long way.